Plugging means for crucibles or the like



Oct. 4, 1932.

INVENT Donald CT Dzcksarz HIS ATTORNEY Q A S;

Patented Oct. 4, 1932 UNITED DONALD C. DICKSON, OF MONTGLAIR, NEW JERSEY IPL'UGGING MEANS FOR ORUCIBLES OR THE LIKE Application filed September 24, 1931. Serial No. 564,774.

The invention relates to means for plugging or stopping the discharge openings of containers or molten metal and more especially containers in which the metal is reduced to a superheated molten condition by the alumino-thermic or analogous reaction, from which container the superheated metal is discharged to its place of application, as, for example, in the formation of alumino-thermic welds and the like, the fundamental element of the plugging means comprising an agglomerated or caked body of an exothermic mixture of which thermit is a typical example, the body being of suitable form to close the discharge opening or tap hole of the receptacle and preferably being so fashioned as to accurately regulate the time of the discharge of the molten metal through said opening as to insure the best results, the maa terial of the plug or stopper reacting exothermically in a predetermined time and the resultant product mingling with the superheated molten metal from the receptacle and forming a component part of said molten metal in subsequent operations.

The invention is illustrated in the accompanying drawing, in which Fig. 1 is a vertical cross section of a typical crucible for efiecting exothermic reactions with the tap hole closed by the novel plug.

Fig. 2 is a similar fragmentary view show ing the plug enclosed in a thimble.

As the invention finds its most general application in discharging superheated molten steel from a receptacle or container in which the steel has been produced by the exothermic reaction, the plugging or stopping means is shown as applied to a crucible 1 containing a centrally disposed tap hole 2 in its bottom through which the products of the exothermic reaction are discharged. In its simplest application, the invention comprises a caked or agglomerated body of exothermic mixture, such as thermit, fashioned tofit the tap hole of the crucible and preferably made of such size and dimensions as to completely react within a specified time, after ignition by the heat derived from the molten metal in'the crucible, which molten metal has been produced by exothermic reaction. Such a closure is conventionally illustrated at 3 as consisting of a plug of caked or agglomerated exothermic material of such form as to close the tap opening until the mass of the exothermic mixture in the crucible has reacted and attained the desired degree of superheat, when and after which the material of plug 2 will have reacted and been reduced to a like molten condition, thereby freeing the tap openlng.

Preferably the plug or stopper will be formed of the same character of exothermic mixture as that constituting the main body reacted in the crucible, so that, when the plug or stopper is ultimately melted and merged with the main body, it will serve as a salutary addition thereto.

While the invention has been illustrated as a plug of themit applied the tap hole of a crucible, it is obvious that it may be applied with equally good effect to any other receptacle or container in which molten metal is carried, or produced, as, for example, by the alumina-thermic process, and it is desired to accurately time: the discharge of the molten metal. For example, it has been proposed to efi"ect the alumino-thermic reaction in the upper part of the mold, such as is commonly employed in effecting welds by alumino-thermic steel and the like, said upper part of the mold being provided with a basin-like cavity connecting with the interior of the mold space by the usual pouring gate! In such case, the pouring gate is plugged or closed by a; caked body of thermit of such size and form as to be reacted completely at the particular moment when the main body of thermit in the upper part of the mold has also completely reacted and attained the desired degree of superheat for opening when the main body of the thermit 1C or similar material in the container has completely reacted and reached the desired degree of superheat.

Instead of the typical plug form illustrated, the stopper of caked or agglomerated eX-.

ble or the pouring gate of the mold. In

such case, the disks Will be made of suitable size so they Will be reacted and completely melted tofree the discharge opening, When the main body of the molten metal in the crucible or in the basin of the mold has reached the desired degree of superheat.

The particular advantages of the invention reside in the fact that it renders the tapping of the molten metal, resulting from the alumino-thermic method, entirely automatic and permits such tapping to be effected When the molten metal has reached its most effective degree of superheat. Furthermore, the invention eliminates any chance of a freeze up, which is not unusual When solid metal bodies or plugs were employed to close the tap holes or discharge ing of a container of molten metal, comprising a body of caked alumino-thermic mixture fashioned to close said opening.

In testimony whereof I aflix my signature.

DONALD G. DICKSON.

openings in various forms ofapparatus of the character described, and avoids the danger to workmen carrying out the operations, who, under the old systems, Were frequently required to drive the stopper or plug from the discharge opening to permit the molten metal in the receptacle to be discharged. What I claim is: 1. Means for plugging the discharge opening of a container of molten metal, comprising a body of agglomerated eXothermic mixture fashioned to close said opening.

2. Means for plugglng the discharge" opening of a container of molten metal, comprising a body of agglomerated exothermic mixture contained in a thimlole fashioned to fit said opening.

3. Means for plugging the discharge opening of a container of molten metal, comprising a body of agglomerated exothermic mixture contained in a metallic thimble fashioned to fit said opening.

4. A plug for the tap hole of an exothermic reaction receptacle, comprising a caked body of exothermic mixture.

5. A plug for the tap hole of an 'exo thermic' reaction receptacle, comprising a caked body of exothermic mixture of a size to insure the complete reaction of said mixture when the exothermic reaction in the recepta cle has progressed to produce the desired degree of superheat. V

6. Means for closing the discharge open- 

